Fluorinated diphenols and method for their preparation

ABSTRACT

Fluorinated bisphenols having a fluorinated alkyl group and a hydrogen atom upon the methylene carbon atom are prepared at atmospheric pressure or at low pressures from a phenol reactant and a fluorinated aldehyde compound in the presence of gaseous hydrogen chloride or gaseous hydrogen bromide catalyst. The fluorinated bisphenols having the fluorinated alkyl group and a hydrogen atom upon the methylene carbon atom are produced in excellent yields and are used for making flame-retardant polycarbonates and polyester-carbonate copolymers.

This is a division of copending application Ser. No. 221,884, filed Dec.31, 1980, now U.S. Pat. No. 4,365,098.

This invention relates to an improved method of making diphenols havingfluorinated alkyl groups and the compositions made therefrom, and moreparticularly, to an improved method of making diphenols having afluorinated alkyl group and a hydrogen atom upon the methylene carbonatom.

BACKGROUND OF THE INVENTION

Diphenols, otherwise known as bisphenols, are well-known in the art andare commonly used in the preparation of polycarbonates, polyesters,polyester-carbonate copolymers and other polymers and copolymers. It iswell-known that by varying the structures of the monomers used to makethe foregoing polymers and copolymers, substantial changes in variousproperties can be realized, such as changes in impact strength,toughness, transparency, heat distortion limits, dimensional stability,creep resistance, flame-retardancy and the like. It is also desirable toimprove such properties, where possible, by changing or altering thestructure of monomers used in the polymers or copolymers, andaccordingly, it is desirable to provide new and improved monomers toimprove the properties of the resultant polymers. Polycarbonatecompositions having improved flame-retardance are disclosed in U.S. Pat.No. 4,182,838 where halogenated vinylidene diphenols are used to preparehigh molecular weight aromatic polycarbonates. Other halogenatedpolycarbonates have also been obtained by using halogenated monomers asthe main polymer building block. Examples of such polycarbonatecompositions include those derived from tetrabromobisphenol-A andtetrachlorobisphenol-A monomers as disclosed in U.S. Pat. No. 3,028,365.

Fluorine containing polyarylates are described in a paper published inIzvestiya Akademia Nack SSSr, Seriya Khimicheskaya, No. 9, pp.1649-1654, September, 1965, (Chemical Abstracts 64, 8321h (1966).Homogeneous and mixed terephthalic, isophthalic, and the like,polyesters of 4,4'-(hexafluoroisopropylidene)diphenol monomer and of4,4'-[alpha-(trifluoromethyl)benzylidene]diphenol monomer weresynthesized, and it was found that the replacement of CH₃ groups on thecentral carbon atom of the isopropylidene diphenol and the methylenediphenol by CF₃ groups leads to a lowering of the softening points ofhomogeneous and mixed polyesters based thereon. Similar monomers aredescribed in Netherlands patent application No. 6,407,548 filed July 2,1964, and opened for inspection on Jan. 4, 1965. The Netherlandsdisclosure relates to a process for the preparation of polycarbonateresin by reacting phosgene with2,2-bis(p-hydroxphenyl)-1,1,3,3-tetrafluoro-1,3-dichloropropane monomer.The polycarbonate resin was characterized as having very good thermalstability and low vapor permeability. The monomers in the foregoingreferences were prepared from the corresponding phenol, and in allcases, the positions on the central carbon atom of the diphenol havebeen substituted with trifluoro- or chlorodifluoromethyl groups or achlorodifluoro methyl group in combination with a phenyl group.

In U.S. Pat. No. 3,388,097, liquid4,4'-(1,1,1-trifluoroethylidene)diphenol monomer was made fromtrifluoroacetaldehyde hydrate and phenol in the presence of anhydroushydrogen fluoride at 50° C. for 8 hours in a Hastelloy bomb. The liquidproduct was distilled under reduced pressure at 165°-170° C. and 0.5-0.6mm. Hg and was obtained in 40% yield. Polyesters were made from theseperhaloalkyl bisphenols and specified aromatic acid halides. However, itis noted that the acid catalyst used in making the diphenol is anhydroushydrogen fluoride; that the reaction is carried out in a "bomb" so as towithstand the considerable autogenous pressure of anhydrous hydrogenfluoride that exceeds 40 to 150 lbs/in.² at the required reactiontemperatures; and that the reaction product distills at 165°-170° C. atreduced pressure. The bisphenols from which the polyesters of U.S. Pat.No. 3,388,097 are made, have the structure:

    HO--Ar.sub.1 --Z--Ar.sub.1 --OH                            (1)

wherein Ar₁ is para-phenylene, and Z is a divalent radical having theformula: ##STR1## wherein R and R' may be the same or different andrepresent perhalogenated lower alkyl groups, fluorine and chlorine beingthe preferred halogen species, with the provision that R' may representhydrogen when R represents a perfluorinated lower alkyl group. In U.S.Pat. No. 3,388,097, it is disclosed that these bisphenols or diphenolsare prepared by the acid catalyzed condensation of an appropriatehalogenated ketone or aldehyde with two molecules of an appropriatephenol. However, as disclosed above, the acid was hydrogen fluoride gas,and there is no suggestion of solid fluorinated diphenols, or ofpolycarbonates, or of improved flame retardance of the polyestersderived from the fluorinated diphenols or of a non-pressurized or lowpressure gaseous acid catalyst system.

Other halogenated diphenols are disclosed in U.S. Pat. No. 2,435,014 andare obtained by condensing two moles of a t,t-octyl-phenol or -naphtholwith 1 mole of a polyhalogenated carbonyl compound, and the condensingagents are a mixture of concentrated sulfuric acid-acetic acid andhydrogen chloride-acetic acid. The polyhalogenated carbonyl compoundsclaimed in making the condensation products in U.S. Pat. No. 2,435,014are chlorine, bromine or iodine and the examples illustrate chlorineonly as a substituent.

SUMMARY OF THE INVENTION

Accordingly, it is the primary object of the present invention toprovide a novel process for making very pure fluorinated diphenols.

It is another object of this invention to provide a non-pressurized orlow-pressure gaseous acid catalyst system for the preparation offluorinated diphenols from a phenol and a fluorinated aldehyde compound.

Still another object of this invention is to provide solid fluorinatedbisphenols having a fluorinated alkyl or a fluorinated aryl group and ahydrogen atom upon the methylene carbon atom of the bisphenol.

It has now been found that diphenols or bisphenols can be made by mixinga phenol reactant and a fluorinated aldehyde compound in the presence ofan acid catalyst selected from the group consisting of anhydroushydrogen chloride and anhydrous hydrogen bromide at low pressure or atsubstantially atmospheric pressure.

In accordance with the present invention, there is also provided afluorinated bisphenol or diphenol having the general formula: ##STR2##wherein R is a fluorinated alkyl radical or a fluorinated aryl radical,and Y₁, Y₂, Y₃ and Y₄ are each independently selected from the groupconsisting of hydrogen, alkyl radical having from about 1 to about 4carbon atoms, chlorine and bromine. In accordance with the presentinvention, R must be a fluorinated alkyl radical, preferably having fromabout 1 to about 22 carbon atoms or a fluorinated aryl radical havingfrom 6 to 16 carbon atoms. When R is a fluorinated alkyl radical, R maybe a straight chain or a branched fluorinated alkyl radical. In certainpreferred embodiments, R is a perfluorinated alkyl or perfluorinatedaryl radical.

In the process of the present invention, the phenol reactant is definedas phenol itself as well as alkyl, chlorine and/or bromine derivativesof phenol, and the alkyl group of the substituted phenol may be fromabout 1 to about 4 carbon atoms.

By the process of the present invention, improvements in the yields ofthe solid diphenol products are obtained by using anhydrous hydrogenchloride gas or anhydrous hydrogen bromide gas at substantiallyatmospheric or low pressures, that is, without the use of highlypressurized systems generally required and taught in the prior art whenhydrogen fluoride gas is used as the acid catalyst. As used herein, lowpressure is defined as a pressure of less than about 30 lbs/in.². Thus,the process is carried out at pressures ranging from about atmosphericpressure to about 30 lbs/in.². As used herein, the gaseous system atatmospheric or substantially atmospheric pressure is defined as anon-pressurized gaseous system. Although there is no intention of beinglimited to a theory, it is believed that the hydrogen chloride gas andthe hydrogen bromide gas appear to be more effective and more soluble inthe solvent system, and accordingly, the condensation reaction takesplace essentially at atmospheric pressure or low pressure without theuse of a highly pressurized system or a pressure "bomb".

As used herein, fluorinated diphenol or bisphenol is the fluorinateddiphenol of formula (3) with one fluorinated alkyl or fluorinated arylgroup attached to the central or methylene carbon atom positionedbetween the two phenol rings. The terms "central carbon atom" and"methylene carbon atom" are used interchangeably and define the carbonatom positioned between the two phenol rings and having one H and the Rattached thereto in formula (3). The fluorinated diphenols have only onefluoroalkyl or one fluoroaryl group upon the central carbon atom, andaccordingly, there is conservation of fluorine over many of the priorart fluorinated diphenols which have two fluoroalkyl or fluoroarylgroups thereon. In view of the fact that the fluorine determines theprice of the materials, the present invention provides lower costfluorinated diphenol monomers for the preparation of the flame-retardantpolymeric compositions which are made from bisphenol monomers. Inaccordance with the present invention, it has also been found thatsubstantial improvements in yield are realized when the gaseous hydrogenchloride or hydrogen bromide are used as the acid catalysts atatmospheric or low pressures to make the fluorinated diphenols from aphenol reactant and a fluorinated aldehyde compound. Furthermore, it hasalso been found by gas chromatographic analyses that the diphenolsformed by the novel process of this invention, have very high purity.

DETAILED DESCRIPTION OF THE INVENTION

In certain cases, improved flame retardance is imparted to highmolecular weight polymers, such as aromatic polycarbonate resins, byselecting appropriate diphenols to be used with the carbonate precursorin the polymerization reaction. In accordance with the presentinvention, these diphenols are provided by a novel process in which thediphenols have a fluorinated alkyl or a fluorinated aryl group attachedto the central carbon atom, otherwise referred to herein as themethylene carbon atom, positioned between the two phenol rings of thebasic bis(hydroxyphenyl)methane structure and derivatives thereof. Thecentral carbon atom is substituted with a hydrogen atom and with afluorinated alkyl or a fluorinated aryl group as illustrated in generalformula (3) above wherein R, Y₁, Y₂, Y₃, Y₄ are each defined above. Inpreferred embodiments, the fluorinated alkyl group represented by R inthe diphenol is form about 1 to about 22 carbon atoms and may bepartially fluorinated or completely fluorinated (perfluorinated alkylgroup). When any one or all of the positions designated by Y₁, Y₂, Y₃and Y₄ are alkyl radicals, in preferred embodiments the alkyl radicalshave from about 1 to about 4 carbon atoms. Furthermore, the alkylradicals represented by R or by Y₁, Y₂, Y₃ and Y₄ in the diphenol may bestraight chain or branched chains or mixtures thereof. When R representsa fluorinated aryl group, the aromatic substituent may contain from 6 to16 carbon atoms in which one or all of the hydrogen are replaced byfluorine.

It will be noted that the methylene carbon atom positioned between thetwo phenol rings has one hydrogen atom, and consequently, there islittle or no steric hindrance in the molecule around the central carbonatom. Therefore, all positional isomers of the fluorinated diphenolstructures or mixtures thereof can be made in accordance with thepresent invention from the phenol reactants, including phenol and thephenol derivatives, and the fluorinated aldehyde compound. Thus, whileall positional isomers of the fluorinated diphenols of formula (3) arepossible, in most cases the isomers are mainly ortho and para, that is,the hydroxy groups are in the ortho and para positions relative to themethylene carbon atom positioned between the two phenol ring structures.In the most preferred embodiments, the isomer is a para, para' isomerwhen the diphenol monomer is used in conjunction with carbonate andester precursors and/or other monomers to make polymers or copolymers.

Typical examples of fluorinated diphenols which may be made by theprocess of the present invention include for example,4,4'-(2,2,2-trifluorethylidene)diphenol having a melting point of 87° C.to 89° C., 4,4'-(2,2-difluoroethylidene)diphenol,4,4'-(pentafluoropropylidene)diphenol,4'-2-(2,2,2-trifluoroethylidene)diphenol,2,2'-pentafluoropropylidene)diphenol,4,4'-(perfluorooctylidene)diphenol, 4,4'-(perfluorodecylidene)diphenol,4,4'-(octafluorobutylidene)diphenol, and the like, including variouscombinations of fluorinated alkyl groups ranging from about 1 to about23 carbon atoms, wherein R in the foregoing equation (3) represents from1 to about 22 carbon atoms; and 4,4'-(pentafluorobenzylidene)bisphenol,4,4'-(pentafluorobenzylidene)bis(2,6-dimethylphenol),4,4'-(pentafluorobenzylidene)bis(2-methylphenol), and the like includingvarious combinations of fluorinated aryl groups ranging from 6 to 16carbon atoms, wherein R in equation (3) represents from 6 to 16 carbonatoms. In the foregoing list of diphenols, the complete alkyl group isabout 2 to about 23 carbon atoms, and the complete aryl group is about 7to about 16 carbon atoms when the methylene carbon atom located betweenthe phenol rings is included in the alkyl group. Most of the fluorinateddiphenols of the present invention are solids at room temperature andare prepared by combining or mixing the appropriate phenol reactant withthe appropriate fluorinated aldehyde compound in the presence of acatalytic amount of an acid catalyst selected from the group consistingof anhydrous hydrogen chloride and anhydrous hydrogen bromide.

The fluorinated diphenols used in the present invention are preferablymade from fluorinated aldehydes which are commercially available in theform of the free aldehyde, the aldehyde hydrate, the aldehyde hemiacetalor the acetal. However, any form of the fluorinated aldehyde may be usedin accordance with the present invention including the foregoing listedforms, the free form of the aldehyde, the trimer or tetramer form of thealdehyde, the cyclic form of the aldehyde, polymeric forms of thealdehyde and the open-chain form of the aldehyde. Examples of thefluorinated aldehyde compound include perfluoroacetaldehyde,perfluoropropionaldehyde perfluorobutyaldehyde, perfluorooctanaldehydeperfluorobenzaldehyde, or any of the partially or completely fluorinatedalkyl aldehydes, straight chain or branched, having from about 2 toabout 23 carbon atoms or any of the partially or completely fluorinatedaryl aldehydes having from 7 to 17 carbon atoms. The foregoingaldehydes, including mixtures thereof, are reacted with the desiredphenol reactants, including herein phenol and phenol derivatives, in anacid catalyzed reaction to form the fluorinated diphenols of the presentinvention. In preferred embodiments, an excess of the phenol reactant isused in the reaction. The ratio of phenol reactant to aldehyde is notcritical as long as there is a sufficient amount of the phenol reactantto react with the fluorinated aldehyde to provide the fluorinateddiphenols. The preferred fluorinated aldehyde compounds are generallythe perfluorinated aldehyde compounds.

Any appropriate phenol, substituted phenol or phenol derivative may beused in the reaction mixture to make the diphenols and are designatedherein as phenols, phenol reactants or phenol compounds. The preferredphenol reactant is generally phenol itself. Other phenols include, forexample, o-cresol, 2,6-xylenol, 6-chloro-orthocresol, orthocholorophenolor any phenol compound substituted with alkyl radicals having preferablyfrom about 1 to about 4 carbon atoms, chlorine or bromine and having atleast one replaceable hydrogen on the ring.

The acid catalysts used in the process of the present invention arecritical and include only gaseous hydrogen chloride and gaseous hydrogenbromide used at substantially atomspheric pressure or low pressure (ator less than about 30 lbs/in.²). Pressure, pressure bombs and pressurevessels are not necessary in the process of the present invention, andthe reaction process steps of the present invention can be carried outat even atmospheric pressure without the necessity of pressure orpressurized vessels. Gaseous hydrogen fluoride acid is disclosed as acidcatalyst in U.S. Pat. No. 3,388,097, however, it requires a pressurebomb capable of withstanding at least 200 lbs/in.² pressure andexceptionally long periods of time to catalyze the reaction underrelative rigorous conditions, and it appears that oils or liquids ofunknown composition in low yield rather than solid fluorinated diphenolsin high yield are obtained from the reaction of the phenol compound andcertain of the fluorinated compounds when anhydrous hydrogen fluoride isused under pressure as the acid catalyst by the prior art technique.

The solid fluorinated diphenols of the present invention may be made bymixing the phenol reactant and the fluorinated aldehyde compound in thepresence of gaseous hydrogen chloride and/or hydrogen bromide acidcatalyst in any desired manner at atmospheric or substantiallyatmospheric pressures or at low pressures not exceeding about 30lbs/in.². For example, the molten phenol may be saturated with thegaseous HCl or HBr, and the fluorinated aldehyde compound may begradually introduced into the non-pressurized reaction vessel containingthe molten phenol.

Although external heat is not required in the reaction of the phenolcompound and the fluorinated aldehyde compound to produce the solidfluorinated diphenols in the presence of the gaseous HCl or HBr acidcatalyst, it is preferred to heat the reaction mixture above ambient upto about 200° C., depending upon the nature of the acid catalyst.Optimum temperatures are generally about 40° C. to about 140° C. Theacid catalyst material is present in a catalytic amount, however, theamount of acid is generally an amount which saturates the phenol and/orthe reaction mixture in which water and/or alcohol are formed during thereaction. In preferred embodiments, the acid catalysts are anhydrous sothat they will not introduce water into the reaction mixture, althoughit is understood that water and/or alcohol are formed in thecondensation reaction leading to diphenols, depending upon the nature ofthe aldehyde precursor employed.

It is also possible to use co-catalysts, such as, mercaptans and othersulfhydryl-containing compounds, with the acid catalyst to speed up theproton-catalyzed reaction. Optional steps include separation of theisomers, for example, by recrystallization, by distillation or bysolvent separation techniques to separate the o,o' and o,p' from thep,p' isomers.

The chlorination or bromination of the fluorinated diphenol may becarried out before the diphenol is formed or after the diphenol isformed by conventional halogenation techniques when the chlorine orbromine derivatives of the fluorinated bisphenol are desired. Forexample, the phenol compound or compounds used to make the diphenols maycontain the chlorine or bromine radicals or mixtures thereof beforereaction with the appropriate fluorinated aldehyde, or the bromine orchlorine radicals or mixtures thereof may be placed upon the fluorinateddiphenol after it has been synthesized from the phenol compound and theappropriate fluorinated aldehyde. When alkyl derivatives of thefluorinated diphenols are desired, they are best prepared from thecorresponding alkylphenol precursors, such as, o-cresol, 2,6-xylenol,o-isopropylphenol, o-tertiarybutylphenol, 2-chloro-6-methylphenol andthe like.

The following specific examples describe the novel diphenol compositionsand the novel process of making the diphenol compositions of the presentinvention. They are intended for illustrative purposes only and shouldnot be construed as a limitation.

EXAMPLE 1 Preparation of 4,4'-(1H-1,1-perfluorooctylidene)bisphenol##STR3##

Into a one liter three-necked flask equipped with an electric stirrer,gas inlet tube reaching below the surface of the reaction mixture,thermometer and reflux condenser are placed 380 g of phenol (4 moles)and 83.2 g (0.2 mole) of perfluorooctanaldehyde hydrate. The mixture isheated to 60° C., when anhydrous hydrochloric acid gas is introducedwith good stirring, until saturated, then, at lower rate so as tomaintain an excess of it continuously in the reaction mixture at thattemperature. The progress of the reaction is followed by gaschromatography, which indicated the formation of very little of theo,o'- and o,p', but mostly of the p,p'-isomer. The warm slurry wasfiltered, the filter cake rinsed twice with cyclohexane andrecrystallized from methylene chloride. The pure white crystals, whichhad the correct analytical composition data for C₂₀ H₁₁ F₁₅ O₂, werefound to be 99.5% pure by gas chromatography and to have a sharp meltingpoint of 138°-139° C. The p,p'-isomeric structure was confirmed byproton nmr, which displayed the AB quadruplet characteristic forparadisubstituted benzene rings.

EXAMPLE 2 Preparation of 4,4'-(1H-1,1-perfluorobutylidene)bisphenol##STR4##

The procedure of Example 1 was repeated, except that theperfluorooctanaldehyde hydrate was replaced with 48.8 g (0.2 mole) ofperfluorobutyraldehyde ethylhemiacetal. When gas chromatographyindicated no change in the composition of the reaction mixture, theexcess phenol was removed by distillation under water aspirator vacuumto yield a residue of 62 g, which is 84% of the theoretical amount andwhich by gas chromatographic analyses contained 93.4% of the p,p'- and5.2% of the o,p'-isomer. Recrystallization from benzene yielded whitecrystals of 99.4% purity, that melted sharply at 117°-118° C. and wereshown to be the p,p'-isomer by the characteristic AB quadruplet in thenmr.

EXAMPLE 3 Preparation of4,4'-(1H-trifluoroethylidene)bis(2-methylphenol) ##STR5##

Repeating the procedure of Example 1, but replacing the phenol with 432g (4.0 moles) of o-cresol and the perfluorooctanaldehyde hydrate with26.0 g (0.2 mole) of trifluoroacetaldehyde methyl hemiacetal, yieldedafter stripping-off the excess o-cresol in vacuum at the end of thereaction a pale yellow residue that was recrystallized from a mixture ofcyclohexane benzene. The white crystals were obtained in 94% yield, hada melting point of 58°-60° C. and were 99.6% pure by gas chromatographicanalysis.

EXAMPLE 4 Preparation of4,4'-(1H-trifluoroethylidene)bis(2,6-dimethylphenol) ##STR6##

Repeating the procedure of Example 3 with 488 g (4 moles) of 2,6-xylenolin place of the o-cresol, yielded title compound in 92% yield, whichafter recrystallization from cyclohexane melted sharply at 83° to 84.5°C. and were 99.1% pure by gas chromatographic analysis.

EXAMPLE 5 Preparation of 4,4'-(1H-trifluoroethylidene)bisphenol ##STR7##

When the procedure of Example 3 was repeated with 380 g (4 moles) ofphenol replacing the o-cresol, to yield title compound in 93.5% yield,that after recrystallization from cyclohexane-benzene melted at 87° to89° C. and was shown to be the 99.8% pure p,p'-isomer by the ABquadruplet in its proton nmr spectrum.

EXAMPLE 6 Preparation of 4,4'-(pentafluorobenzylidene)bisphenol ##STR8##

The procedure of Example 1 was repeated, except that theperfluorooctanaldehyde hydrate was replaced with 39.2 g (0.2 mole) ofpentafluorobenzaldehyde and the gaseous hydrochloric acid catalyst withgaseous hydrobromic acid. After the distillation of the excess phenol,the residue showed by gas chromatography the presence of 12.6% of2,2'-(pentafluorobenzylidene)bisphenol, 37.0% of2,4'-(pentafluorobenzylidene)bisphenol and 50.4% of4,4'-(pentafluorobenzylidene)bisphenol. The latter was isolated byrecrystallization from cyclohexane.

EXAMPLE 7 Preparation of4,4'-(pentafluorobenzylidene)bis(2,6-dimethylphenol) ##STR9##

The procedure of Example 4 was exactly repeated, except that thetrifluoroacetaldehyde methyl hemiacetal was replaced with 39.2 g (0.2mole) of pentafluorobenzaldehyde. After 2 hours of contacting thereaction mixture with hydrochloric acid gas, the excess xylenol wasremoved by vacuum distillation, and the bright yellow product, that wasobtained in 98% yield, was recrystallized from cyclohexane. Thesulfur-colored crystals melted sharply at 157° to 159° C. and were shownto be 99.3% pure by gas chromatography.

EXAMPLE 8 Preparation of4,4'-(pentafluorobenzylidene)bis(2-methylphenol) ##STR10##

Repeating the procedure of Example 3, but replacingtrifluoroacetaldehyde methyl hemiacetal with 39.2 g (0.2 mole) ofpentafluorobenzaldehyde, yielded the following composition:2,2'-(pentafluorobenzylidene)bis(6-methylphenol) 4.5%;2,4'-(pentafluorobenzylidene)6,2'-dimethylbisphenol) 35.7% and4,4'-(pentafluorobenzylidene) bis(2-methylphenol) 59.8%.Recrystallization from cyclohexane yielded pale yellow crystals of the4,4'-isomer, which melted at 111° to 113° C. and were of 95.2% purity.

While the invention has been described with respect to preferredembodiments, it will be apparent that certain modifications and changescan be made without departing from the spirit and scope of the inventionand, therefore, it is intended that the foregoing disclosure be limitedonly by the claims appended hereto.

What is claimed is:
 1. An improved method of making bisphenols having afluorinated alkyl of 1 to about 22 carbon atoms or fluorinated arylgroup of 6 to about 16 carbon atoms and a hydrogen atom upon themethylene carbon atom of the bisphenol comprising mixing at low pressureor up to about 30 lbs/in. sq. a phenol reactant and a fluorinated alkylof 2 to about 23 carbon atoms or aryl of 7 to about 17 carbon atomsaldehyde compound in the presence of an acid catalyst selected from thegroup consisting of anhydrous hydrogen chloride and anhydrous hydrogenbromide.
 2. The method of claim 1, further comprising heating themixture at a temperature ranging from ambient to about 200° C.
 3. Themethod of claim 1, wherein the phenol is substituted with hydrogen,chlorine atoms, bromine atoms, alkyl radicals or mixtures thereof. 4.The method of claim 3, wherein the alkyl radicals have from about 1 toabout 4 carbon atoms.
 5. The method of claim 1, comprising mixing about2 moles of the phenol for about every 1 mole of the fluorinated aldehydecompound.
 6. The method of claim 1, wherein the fluorinated aldehydecompound is in the form selected from the group consisting of the freeform of the aldehyde, the hydrate, the hemiacetal form, the acetal form,the trimer form, the tetramer form, the cyclic form and the open chainform.
 7. The method of claim 1, wherein the fluorinated aldehydecompound is perfluorinated.
 8. The method of claims 1, 6 or 7, whereinthe fluorinated aldehyde compound is a fluorinated alkyl aldehyde havingfrom about 2 to about 23 carbon atoms.
 9. The method of claims 1, 6 or 7wherein the fluorinated aldehyde compound is a fluorinated aryl aldehydehaving from about 7 to about 17 carbon atoms.
 10. The method of claim 1wherein the phenol reactant is selected from the group consisting ofphenol, alkyl derivatives of phenol wherein the alkyl group has fromabout 1 to about 4 carbon atoms, phenol substituted with chlorine andphenol substituted with bromine.